Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 84 for “"light availability"”.
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Effects of Light Availability and Canopy Position on Peach Fruit Quality
… were conducted to determine the influence of light on 'Norman' and 'Cresthaven' peach fruit quality characteristics. Of primary interest was the relationship between ground color and flesh firmness. Light levels were manipulated by use of shade cloth, reflective mulch, and aluminum foil. …
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Characterising responses of the seagrass Posidonia Sinuosa to changes in light availability
… threat of seagrass loss resulting from reduced light availability has motivated this characterisation of responses of Posidonia sinuosa Cambridge et Kuo to light availability and their application as monitoring tools. The study comprised of three major components: an assessment of P. sinuosa …
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Litter Conditioning is Differentially Affected by Leaf Species, Phosphorus Enrichment, and Light Availability
… P concentrations (0, 0.05, and 0.5 mg SRP/L) and light availability (15 and 500 µmol photons m-2 s-1). Results of the first experiment showed that litter %P increased and C:P decreased with increasing water column P concentrations and this response was greater for the more labile maple species. …
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Interacting effects of soil nitrogen supply and light availability on understory sapling growth and foliar attributes
Light availability in forest understories is a well recognized constraint on sapling growth, but limitations in soil nitrogen (N) availability, and the link to foliar photosynthetic capacity, typically receive less consideration in describing stand dynamics. My primary hypothesis is that light and …
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Examining Melt Pond Dynamics and Light Availability in the Arctic Ocean via High Resolution Satellite Imagery
… ponds”) forming on its surface, which enhance light transmission to the ocean. Changes in the timing and distribution of melt pond formation and associated increases in under-ice light availability are the primary drivers for seasonal progression of water column primary production and warming. …
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The Influence of Overstory Structure on Understory Light Availability in a Longleaf Pine (Pinus palustris Mill.) Forest
Understory light environments are inherently heterogeneous and therefore difficult to characterize. Numerous methods to measure understory light have been assessed in closed-canopied forests; however, the reliability of these methods has not been addressed for open-canopied forests. Therefore, the …
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Phytoplankton community structure, productivity and nitrogen metabolism as a function of light availability in the Atlantic sector of the southern Ocean by Erika Anne Kean.
… each providing a natural laboratory to test lightdependent uptake of both oxidised and reduced N species.
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On the ecology of Acer circinatum Pursh: a study of factors that affect the distribution of a small hardwood tree within oldgrowth forests in southwestern British Columbia, Canada
… Columbia. The influence of surficial geology, light availability, ground water levels, aspects of the microtopography and of vine maple persistence, priority effects and layering on the distribution pattern of vine maple within oldgrowth stands was investigated in this study. The distribution …
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Increased phenotypic plasticity linked to broader geographic range size in sunflower (Helianthus) species
… species can hinder these processes. Changes in light availability from human activities impact the growth and fitness of broadleaf species like sunflowers (Helianthus spp.). In a garden experiment, we compared the phenotypic plasticity of five Helianthus species representing different geographic …
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Discerning Differences in the Plant Traits of the Floral Communities of Mt. Washington, NH, by Incorporating Intraspecific Variability Analysis
… differences associated with canopy closure (light availability). Comparing plant traits along this elevational gradient, from alpine to sub-alpine using measures of intraspecific variability, allows us to investigate any underlying effects. These include differences in air temperature, light …
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The Influence of Changing Nutrients and Warming on Phytoplankton and its Interactions with Zooplankton in the North Sea
… strengths increase under low nutrient and light availability. Bottom-up strength (from primary producers to grazers) is highest under high light availability, N:P between 20 and 25, and intermediate SST; whereas top-down strength (from grazers to primary producers) dominates under lower …
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Survival strategies of eelgrass in reduced light
<p>Light reduction due to anthropogenic impacts is the most widespread cause of worldwide decline of eelgrass, an ecologically important marine angiosperm whose role in supporting overall coastal ecosystem productivity has been widely recognized. Understanding eelgrass plant and meadow responses to …
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Regeneration Dynamics in Old -Growth and Second-Growth Southern Appalachian Cove Forests
… The effects of disturbance and seasonal light availability, as measured by the analysis of hemispherical photographs, were expected to be the major sources of variation explaining differences in regeneration composition and dynamics. Overall seasonal light availability was not found to be …
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Algal bioproducts : investigating the effect of light quality on metabolite production by photosynthetic diatoms
… of environmental growth conditions including light. To achieve this, laboratory scale photobioreactors were used to continuously monitor environmental factors to record biological responses of 𝘊. 𝘮𝘶𝘦𝘭𝘭𝘦𝘳𝘪 to different environmental conditions including light wavelengths. A brief introduction …
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Sex Allocation in the Caribbean Coral, <em>Porites astreoides</em> (Lamarck)
… be manipulated to maximize fitness when energy availability limits reproduction. Sex allocation theory has been primarily developed in plants, but may be applicable to other sessile organisms that are subject to similar selective pressures. Like plants, reef building corals depend on …
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The effects of terrestrial sediment inputs on ecosystem functions in seagrass meadows and unvegetated sediments
… suspension of fine sediments can reduce seafloor light availability and long-term accumulations increase sediment mud content (particles < 63 µm), both of which could have significant consequences on ecosystem functioning. Understanding how ecosystem functioning may respond to environmental change …
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The importance of cotyledon functional morphology and patterns of seed reserve utilization for the physiological ecology of neotropical tree seedlings
… seedling growth starts to depend on the external light availability. Overall, species with smaller seeds develop cotyledons with a larger photosynthetic capacity. Concentrations of energy and nitrogen reserves in seeds vary up to three fold among species and are independent of total seed mass or …
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Seasons in the Stream: River Ecosystem Phenology in a Changing Climate
… are primarily dictated by seasonal factors like light availability and temperature. In small rivers, primary productivity often peaks opposite that of terrestrial ecosystems, where overhanging canopies shade the river channel impeding light reaching the water surface. The degree to which river …
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Understory Composition, Seedling Growth, and Snag Frequency Across a Water-Limited Forest Landscape
… communities to soil moisture, nitrogen, and light, and to understand whether responses to soil moisture depend on the latter two. I measured functional traits (individual-level plant characteristics) of understory vascular plants and modeled the composition and diversity of understory plant …
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Saltcedar (Tamarix spp.) in the Northern Great Plains: Seed Ecology and Cultural Considerations
… South Dakota as related to soil moisture, light availability, and distance from seed source. In June 2011, a total of 120 plots were established in each of three moisture levels (40 plots per level) at each site. Moisture levels were categorized as: 1) wettest, 2) moderate, and 3) driest …
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